1. Field of the Invention
The present invention relates to a measurement system for measuring skin impedance (i.e., a resistance value) in a small region of the skin and an electrode used in the measurement system. More particularly, the present invention relates to an impedance measurement electrode separately provided with a current supply electrode and a measurement electrode for measuring skin impedance in a small region of the skin and an impedance measurement system using the same.
2. Description of the Related Art
Since the results of an analysis of skin impedance values in a small region of the skin are used in a variety of applications, a method and apparatus for accurately measuring skin impedance have been researched and developed. In general, conventional technology of measuring skin impedance is used to detect meridian points on the skin, which are used to diagnose a disease and treat the disease in the field of Chinese medicine.
A meridian point, which is used in Chinese medicine or hand therapy (such as acupuncture, moxibustion, and massage), is a reaction point in the skin or a muscle. A meridian system is a channel connecting multiple reaction points. In the view of Chinese medicine, and more particularly hand therapy, the human body includes internal organs (i.e., the five viscera and the six entrails). Under healthy conditions, the functions of these internal organs harmonize with one another. Under unhealthy conditions, the harmony among the functions of the internal organs is disrupted and symptoms of a certain disease may be present. An energy circulating system (in which vital energy and blood flows), which passes through the human body, inside and outside thereof, and controls the functions of the internal organs, is a meridian system.
Accordingly, it is critical to accurately locate the positions of the meridian points and the meridian system for diagnosis and treatment in Chinese medicine. The meridian points and the meridian system can be accurately located by measuring skin impedance based on the principle that regions corresponding to the meridian points and the meridian system have a lower electrical resistance than other skin regions.
In addition, it has been reported that by measuring the skin impedance it is possible to diagnose cutaneous cancer, determine the degree of a burn, detect motion, detect a capacity for rehabilitative exercise, and determine normality or abnormality of a lymph node in the skin. As such, it is expected that various techniques based on measuring skin impedance will be increasingly used.
However, most conventional methods of measuring skin impedance are performed on the whole body rather than in a small region of the body. Moreover, most conventional methods of measuring skin impedance either on the whole body or in a local region of the body use only two or three electrodes. In that conventional arrangement, at least one electrode serves as both a measurement electrode and an electrode applying voltage or current. Accordingly, in addition to real skin impedance obtained from the dermis and the subcutis, a contact resistance and an epidermis impedance are included in a measured value. Thus, it is impossible to accurately measure the skin impedance because of the contact resistance and epidermis impedance.
More particularly, the measured value of the contact resistance varies significantly with a measurer's skillfulness (for example, an ability to control the contact speed and the contact pressure of an electrode) and conditions of a skin surface contacting an electrode, e.g., temperature and humidity, thereby significantly affecting the measured value of skin impedance.
Accordingly, it is difficult to obtain an accurate measured value of skin impedance using conventional techniques.